I’ve read lots of novels where one or more of the characters play sport, often informally. For example, many of the characters in the Trinity Lakes Romance series play in the town’s annual Aussie Rules football game.
I’ve also read and enjoyed a fair few novels where one or both of the main characters are professional sportspeople.
Falling for Maddie Grace by Meredith Resce is an excellent novella featuring a professional Aussie Rules player and a female referee. I’ve read this one multiple times, and it’s a lot of fun.
Several novels in Susan May Warren’s Christiansen Family series features pro sportsmen, including It Had to Be You, When I Fall In Love, and You’re The One That I Want.
But the Christian author who first comes to mind when I think about sports romance is Carolyn Miller. Her Original Six series each follows a professional ice hockey player in one of the “original six” professional teams, and she is now following this up with the Northwest Ice series. I’ve read all the Original Six (my favourite was Big Apple Atonement), and now I’m working my way through the Northwest Ice series.
